Testing systems for integrated circuits contained on a motherboard include a docking assembly for aligning a test head to a semiconductor performance board device handler. As seen in U.S. Pat. No. 4,352,061 vacuum fixtures have been heretofore employed for connecting test points on a circuit board to test probes within a platen. The board to be tested is pulled down by vacuum to make electrical contact with probes which have been moved to a test position dictated by the pattern of test points on the board to be tested. In U.S. Pat. No. 5,150,042 an automatic semiconductor wafer test probe apparatus is disclosed wherein a wafer is vacuum held on a magnet on an X-Y-Z chuck. The chuck is moved to bring the wafer test sites into contact with a set of test probes. U.S. Pat. No. 4,771,234 shows a vacuum activated test fixture for boards where a board is sealed on a vacuum chamber and moved by suction into securement and electrical contact with electronic components under test. U.S. Pat. No. 4,527,942 discloses an electronic test head positioned particularly for testing semiconductor wafers which utilizes a clamping system with location pins inserted into openings in a handler plate while a test connector mates with the device being tested.
The related application discloses a test head interface including a plate, vacuum cups and guiding pins which mate with apertures in a stacking block. While in some usages the interface, which includes four vacuum cups, is operational, problems have arisen. These problems included poor vacuum holding, bending of the plates holding the vacuum cups, buckling of the vacuum cups, attendant release of vacuum, and the need for additional clamping between the plate and the test head. Hook and bail (fishing tackle box-type) clamps were added as an expedient to improve performance. Stiffer i.e., thicker, plates have been used in other attempts to solve these problems.